The RAM disk will be seen as a normal drive. Suggest you locate a utility to create a Ram Disk then:
Go into AutoCAD settings and go to the profile tab and create a new profile.
Now set all the applicable file location paths to point to the Ram Drive.
I would play around with setting a current profile from the original to the new one when you close autocad.
Then you will see how AutoCAD behaves when it starts up. The point is you will need to have your workflow in place to ensure the Ram Drive is in place prior to starting AutoCAD. As part of this workflow you would want to use a batch file to perform a bulk copy (or a bulk copy utility such as snytron) to copy all the required working files to the ram drive.
You would also want to run a utility that performs an aoutbackup every 10 min or so to your normal hard drive. This will keep your data intact should you have a power outage.
Now the Flip Side:
If you were to work off a solid-state NVME drive you may see the performance gain you are looking for without going through all the trouble / risk associated with a volatile ram drive. It is true the bandwidth of the two are about equal but the DDR4/5 memory is far better at accessing small bits of data. BUT you may not actually y see that full performance gain or see enough of that performance gain to be worth the trouble as you are not performing bulk copy transfers but rather accessing data through the AutoCAD application itself. It would be worth a test if you have the time
it would have been worth it for sure if we were in the 1990s and early 2000s but things are a bit faster now.
That's my 2 cents, hope it gives you some ideas.
Best Regards
-Tim C.
A 1Tb Nvm drive is $80.00 now